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1
Liu, Qunling. "Post mid-Cretaceous sequence stratigraphy and depositional history of northeastern Gulf of Mexico /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Smith, Jason J. "A reinterpretation of the sedimentology and stratigraphy of the upper Silurian-lower Devonian Manlius Formation in upstate New York." Diss., Online access via UMI:, 2009.
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Stukins, Stephen. "Spatial and temporal palynological trends in marginal marine depositional system : Lajas Formation, Neuquén Basin, Argentina." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=167073.
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In order to better understand the relationship of tidally dominated depositional environments and their palynological assemblages, the Middle Jurassic sediments of the Lajas Formation, Neuquén Basin were examined. The ambition was to present models and trends which can be used for studies of other such deposits. In order to integrate the palynoassemblages with the environment of deposition, additional granulometric data and nutrient data from XRF analysis were used in combination with the palynology. A new method using correspondence analysis was used for understanding the palaeoecology and floral dynamics. An updated, dynamic model for the Middle Jurassic floral palaeoecology of the Neuquén Basin has been presented and the drivers of floral succession are interpreted as disturbance tolerance and substrate water content. Taphonomic expressions of seral groupings show that later seral stage community palynomorphs are preferentially deposited within or close to distributary systems, whereas earlier seral stage palynomorphs are preferentially deposited in environments of greater accommodation space, such as bayfills. Taphonomic signatures, using palaeoecological groupings provide trends in low (4th/5th) order cycles and lateral variations relating to tidal channels and surrounding bayfill mudstones. A model for 4th/5th order boundaries is also presented using new interpretations of the distribution of pinaceous pollen and microforaminiferal test linings. Using Canonical Correspondence Ananlysis (CCA), a model is presented of depositional environments incorporating palynological data and granulometric proxies for grain size and grain sorting. The relationship between sediment processes in a tidal flat dominated palaeoenvironment and the hydrodynamic properties of some palynomorphs is investigated and presented. The weathering and nutrient status of the substrates throughout the Lajas Formation is presented using XRF proxy data. The proxies are also used with CCA to create nutrient related floral groupings. When plotted stratigraphically, these show cycles of eutrophication and subsequent weathering of the substrates.
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Hamlin, Herbert Scott. "Syn-orogenic slope and basin depositional systems, Ozona sandstone, Val Verde Basin, southwest Texas /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Alexander, Alan John. "Palynological, stratigraphic and chemical analyses of sediments in the Lothians with particular reference to the Lateglacial." Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/10626.
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Palynological and stratigraphic investigations have been conducted on sediment cores for three sites in Lothian Region, Scotland: Balgone House, Broxmouth and Corstorphine. All phases of the Lateglacial period, as far as they are manifested in the Lothians at the sites studied, have been investigated with particular reference to the Younger Dryas, the main Interstadial, or Allerod, and also the evidence for the colder conditions that preceded it which are presumed to represent Older Dryas-type vegetation. Further light has been cast on the development of the Postglacial broad - leaved forests. The Cambridge computer program POLLDATA MKV was used to perform the necessary calculations and controlled a graph plotter to generate pollen diagrams. A series of subroutines is described that translated the calls to the Cambridge graphics subroutine library. This may serve as a model for other installations. Objective numerical zonation methods are applied to the pollen data. These methods are used not only to zone the pollen series but also to aid in the generation of hypotheses regarding vegetation changes. Chemical analyses of the sediments from Balgone House were undertaken. The results obtained are at variance with those from published work and it is proposed that the reason is that the chemical pre-treatment of samples employed locally may be less efficient in leaching the cations from the mineral fraction.
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Hill, Robert E. (Robert Einar). "Stratigraphy and sedimentology of the Middle Proterozoic Waterton and Altyn Formations, Belt-Purcell Supergroup, southwest Alberta." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63330.
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Hines, Frederick Michael. "The sedimentation, tectonics and stratigraphy of the cretaceous/tertiary sequence of northwest Santander, northern Spain." Thesis, University of Oxford, 1986. http://ora.ox.ac.uk/objects/uuid:1d1f8c32-9fd3-44a5-ba6a-d963fa9868c0.
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The facies evolution of the Cretaceous/Tertiary sequence of NW Santander is considered in relation to the Cretaceous rifting and drifting, and Tertiary partial closure of the Bay of Biscay. Overlying the Palaeozoic basement are the fluvial Lower Triassic Buntersandstone and Upper Triassic Keuper evaporitic mudstone, deposited in a failed rift, extensional basin. Overlying Lower Jurassic carbonates are the syn-rift, continental elastics of the Vealden deposited in halfgrabens cut by transfer faults. The Vealden consists of two formations:- the lower, arenaceous-rich Barcena Mayor Fm. (braided stream environment) and the upper, argillaceous-rich Vega de Pas Fm. (meandering river). Overlying it is the Aptian Umbrera Fm. (calcarenite sheet), the Patrocinio Fm. (shoaling-up ward sandstone/marl alternation), the San Esteban Fm. (requienid/foraminiferal biomicrite of the internal platform) and the marls of the Rodezas Fm. The Upper Aptian Reocin Fm. is a requienid/foraminiferal biomicrite with thinned calcarenites deposited over active, diapiric palaeohighs. After initial marine and then equant calcite (meteoric phreatic) cementation, invasion of meteoric-derived groundwater over palaeohighs generated lenses of sucrosic dolomite in the Reocin Fm. Local mixing of further groundwater and Keuper-derived, sulphate-rich waters in karstic caverns precipitated sparry, baroque dolomite and Pb/Zn sulphides (by bacterial sulphate reduction). The clastic Lower Albian is a transgressive fluvial/estuarine/inner shelf sequence with tidal estuarine channels and sandwaves. The Middle/Upper Albian (syn-drift) has basal calcarenitic tidal sandwaves and is followed by storm/wave-reworked carbonates deposited on a homoclinal ramp. The clastic Lower Cenomanian is an estuarine/inner shelf deposit with tidal sandwaves and sandbars. The Middle/Upper Cenomanian is a storm/tide-dominated calcarenite. Outer shelf marls occur in the Turonian to Middle Campanian and the Upper Campanian to Middle Eocene is a sandy, foraminiferal inner shelf limestone. The Upper Eocene/Oligocene (syn-compression) is a carbonate slope-apron-reefal flysch deposit. It includes hemipelagic marl, neritic-derived calcarenitic turbidites and rudaceous mass flow deposits with highly polymict conglomerates. These were deposited coevally with Keuper piercement and thrust reactivation and date the Pyrenean compressional deformation here.
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Sinclair, Hugh D. "The North Helvetic Flysch of eastern Switzerland : Foreland Basin architecture and modelling." Thesis, University of Oxford, 1989. http://ora.ox.ac.uk/objects/uuid:0e83a6d2-cf51-4dd3-b4bb-523a1d28fc90.
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The North Alpine Foreland Basin (NAFB) comprises sediments of late Eocene to middle Miocene age. The earliest deposits are the North Helvetic Flysch which are exposed in the regions of Glarus and Graubunden, eastern Switzerland. The Taveyannaz sandstones are the first thrust wedge (southerly) derived sediments of the North Helvetic Flysch. The Taveyannaz basin was divided into two sub-basins by a thrust ramp palaeohigh running ENE/WSW (parallel to the thrust front). Palaeocurrent directions were trench parallel towards the ENE. Sedimentation in the Inner basin (140m thick) is characterised by very thick bedded turbidite sands generated by thrust induced seismic events confined within the thrust-top basin. The Outer basin (240m min. thickness) comprises 10-15 sand packages (5-100m thick) formed by turbidite sands which are commonly amalgamated. Sedimentation in the Outer basin is considered to have been controlled by thrust-induced relative sea-level variations. The Inner basin underwent intense deformation at the sediment/water interface prior to the emplacement of a mud sheet over the basin whilst the sediments were partially lithified. Later tectonic deformation involved fold and thrust structures detaching in the underlying Globigerina marls. The stratigraphy of the NAFB can be considered as two shallowing upward megasequences separated by the base Burdigalian unconformity. This stratigraphy can be simulated by computer by simplifying the foreland basin/thrust wedge system into 4 parameters: 1) the effective elastic thickness of the foreland plate, 2) a transport coefficient to describe the erosion, transport and deposition of sediment, 3) the surface slope angle of the thrust wedge, 4) the thrust wedge advance rate. The Alpine thrust wedge underwent thickening during the underplating of the External Massifs at about 24-18Ma. This event is simulated numerically by slowing the thrust wedge advance rate, and increasing the slope angle and keeping all other parameters constant. This event causes rejuvenation of the forebulge, and erosion of the underlying stratigraphy, so simulating the base Burdigalian unconformity without recourse to eustasy or anelastic rheologies to the foreland plate.
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Painter, Clayton S. "The Shannon Sandstone new observations and constraints applied to depositional models /." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1799711431&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Kerns, Jessica L. "Contrasting depositional environments of North American black shales illuminated through geochemical techniques and modern analogs /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1421149.
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Haines, Peter W. "Carbonate shelf and basin sedimentation, late Proterozoic Wonoka Formation, South Australia /." Title page, contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phh152.pdf.
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Lyons, Timothy Williams 1957. "Stratigraphy and depositional environment of the Colina limestone (lower Permian), southeastern Arizona." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/558115.
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Mason, Elizabeth Lane. "Internal facies architecture of a sand-rich, deep-sea depositional system: the rocks sandstone, Reliz Canyon formation, Northern Santa Lucia Range, Monterey County, California /." May be available electronically:, 1998. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Payne, Danielle Sarah. "Shelf-to-slope sedimentation on the north Kaipara continental margin, northwestern North Island, New Zealand." The University of Waikato, 2008. http://hdl.handle.net/10289/2413.
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Temperate mixed carbonate-siliciclastic sediments and authigenic minerals are the current surficial deposits at shelf and slope depths (30-1015 m water depth) on the north Kaipara continental margin (NKCM) in northern New Zealand. This is the first detailed study of these NKCM deposits which are described and mapped from the analysis of 54 surficial sediment samples collected along seven shorenormal transects and from three short piston cores. Five surficial sediment facies are defined from the textural and compositional characteristics of this sediment involving relict, modern or mixed relict-modern components. Facies 1 (siliciclastic sand) forms a modern sand prism that extends out to outer shelf depths and contains three subfacies. Subfacies 1a (quartzofeldspathic sand) is an extensive North Island volcanic and basement rock derived sand deposit that occurs at less than 100-200 m water depth across the entire NKCM. Subfacies 1b (heavy mineral sand) occurs at less than 50 m water depth along only two transects and consists of predominantly local basaltic to basaltic andesite derived heavy mineral rich (gt30%) deposits. Subfacies 1c (mica rich sand) occurs at one sample site at 300 m water depth and contains 20-30% mica grains, probably sourced from South Island schists and granites. Facies 2 (glauconitic sand) comprises medium to fine sand with over 30% and up to 95% authigenic glauconite grains occurring in areas of low sedimentation on the outer shelf and upper slope (150-400 m water depth) in central NKCM. Facies 3 (mixed bryozoan-siliciclastic sand) consists of greater than 40% bryozoan skeletal material and occurs only in the northern half of the NKCM. Facies 4 (pelletal mud) occurs on the mid shelf (100-150 m water depth) in northern NKCM and comprises muddy sediment dominated by greater than c. 30% mixed carbonatesiliciclastic pellets. Facies 5 (foraminiferal mud and sand) contains at least 30% foraminifera tests and comprises two subfacies. Subfacies 5a consists of at least 50% mud sized sediment and occurs at gt400 m water depth in southern NKCM while subfacies 5b comprises gt70% sand sized sediment and occurs at mid to outer shelf and slope depths in the northern NKCM. vi A number of environmental controls affect the composition and distribution of NKCM sediments and these include: (1) variable sediment inputs to the NKCM dominated by inshore bedload sources from the south; (2) northerly directed nearshore littoral and combined storm-current sediment transport on the beach and shelf, respectively; (3) offshore suspended sediment bypassing allowing deposition of authigenic minerals and skeletal grains; (4) exchange between the beach and shelf producing similar compositions and grain sizes at less than 150 m water depth; and (5) the episodic rise of sea level since the Last Glaciation maximum approximately 20 000 years ago which has resulted in much sediment being left stranded at greater depths than would otherwise be anticipated. Sedimentation models developed from other wave-dominated shelves generally do not appear to apply to the NKCM sediments due to their overall relative coarseness and their mosaic textural characteristics. In particular, the NKCM sediments do not show the expected fining offshore trends of most wavedominated shelf models. Consequently, sandy sediments (both siliciclastic and authigenic) are most typical with mud becoming a dominant component in southern NKCM sediments only at greater than 400 m water depth, over 350 m deeper than most models suggest, a situation accentuated by the very low mud sediment supply to the NKCM from the bordering Northland landmass.
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Qing, Hairuo. "Diagenesis and sedimentology of rainbow F and E buildups (Middle Devonian), northwestern Alberta." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65414.
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Walsh, James Leo 1960. "The Hellhole Conglomerate: a study of a mid-Tertiary extensional basin." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/558117.
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Chow, Andre M. C. (Andre Mu-Chin). "Sedimentology and paleontology of the Attawapiskat Formation (Silurian) in the type area, northern Ontario." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65494.
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Dal, Bo Patrick Francisco Fuhr. "Inter-relação paleossolos e sedimentos em lençois de areia eolica da Formação Marilia (noroeste da Bacia Bauru)." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287354.
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Orientadores: Giorgio Basilici, Francisco Sergio Bernardes LadeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: A Formação Marília (Maastrichtiano), na faixa de afloramentos da porção noroeste da Bacia Bauru (estados de Goiás e Mato Grosso do Sul), é interpretada neste trabalho como um antigo sistema eólico de lençol de areia. A sucessão vertical é caracterizada por arenitos muito finos a médios intercalados com paleossolos em espessas sucessões de até 150 metros de espessura. A litofácies Arenito com laminação plano-paralela, que forma corpos com estratificação cavalgante transladante subcrítica, atribuída à deposição de areias com marcas onduladas eólicas é a mais comum descrita na área de estudos. Os paleossolos representam mais de 65% do registro geológico da Formação Marília, constituídos predominantemente por Aridisols caracterizados por concentrações secundárias de carbonato de cálcio. Superfícies suborizontais de deflação eólica separam os depósitos eólicos dos paleossolos e dividem a Formação Marília em duas fases distintas de construção de corpos geológicos ligadas às variações paleoclimáticas: i) fase de sedimentação eólica, caracterizada por depósitos arenosos de marcas onduladas eólicas; ii) fase de paleopedogênese, caracterizada por Aridisols. Ambas as fases se alternaram temporalmente e, registram períodos de formação de diferentes ordens de grandeza, provavelmente maiores que 105 vezes entre a formação dos depósitos arenosos com marcas onduladas eólicas e o desenvolvimento de horizontes Bk dos Aridisols. A alternância cíclica entre depósitos eólicos e paleossolos está ligada a variações paleoclimáticas que controlaram a disponibilidade hídrica no ambiente. Durante os períodos mais secos, a ausência de cobertura vegetal expôs a superfície à ação dos ventos e formação de extensas superfícies de deflação eólica, que posteriormente foram cobertas por depósitos arenosos de marcas onduladas eólicas. Com o posterior restabelecimento da umidade atmosférica e o conseqüente aumento da cobertura vegetal, a superfície foi reestabilizada, inibindo o processo de deflação e deposição eólica e permitindo a formação de Entisols e Aridisols
Abstract: The Marília Formation (Maastrichtian), outcropping in the northwestern portion of the Bauru Basin (Goiás and Mato Grosso do Sul brazilian states), is interpreted here as an ancient Aeolian sand sheet. The vertical succession, c.150 m thick, is made up of very fine to medium-grained sandstone and, it is characterised by cyclic interbedding of sediments and palaeosols. Planar laminated sandstone (subcritically climbing translatent stratification), formed by aeolian sand with wind ripple, is the most common lithofacies. Palaeosols, mainly Aridisols, represent more than 65% of the geological record of the Marília Formation. Subhorizontal aeolian deflation surfaces divide Marília Formation in two distinct constructional phases of geological bodies linked to palaeoclimatic variations: i) phase of prevalent aeolian sand deposition; ii) phase of Aridisols development. The two phases they alternated in time and probably record periods of formation with difference of the order greater than 105 between aeolian sand deposition and development of the Bk Aridisols horizons. Palaeoclimate is the main forcing factor of the Aeolian sand deposition and soil development. Episodes of sedimentation and soil development likely result from cyclic decreases and increases in available moisture and vegetation cover. Aeolian deflation and sedimentation were predominant during drier phases of past climatic cycles, when vegetation cover was sparse in source areas and windier conditions have the capacity to remove and transport clastic materials. During wetter phases of climatic cycles, increased vegetative cover stabilised the landscape, reduced deflation, and intensified Entisols and Aridisols development
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
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Dittmers, Klaus Hauke. "Late Weichselian to Holocene sedimentation in the inner Kara Sea : qualification and quantification of processes = Sedimentationsprozesse in der inneren Kara-See (Spät-Weichsel bis Holozän) /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2006. http://www.gbv.de/dms/goettingen/510037178.pdf.
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Gates, Edward Breed. "The Holocene Sedimentary Framework of the Lower Columbia River Gorge." PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/4801.
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The Columbia River is the largest fluvially dominated estuary in the Pacific Northwest, yet the Holocene transgressive fill of this system has not previously been studied. Nearly 1500 industry borehole and water well records in the lower Columbia River basin (LCRB) were analyzed. These records document the sedimentary infilling of the lower 120 miles of the drowned river valley that occurred during the Holocene marine transgression (10-0 ka) . Of particular importance is a key stratigraphic marker horizon of volcanic tephra that has been identified throughout the LCRB. INAA was used to determine the geochemical composition of the target tephra layer. The tephra geochemistry was then compared to geochemical data from potential Cascade source volcanos to determine whether the tephra layers are geochemically related, and the possible age and source of the tephra. The geochemical comparisons indicate that the suspect tephra horizon was derived from the climax eruption of Mount Mazama approximately 6845 years ago. Cross-sections have been constructed that record the lateral and longitudinal depositional development of the river basin. Sediment grain size distribution data have also been compiled and shows that grain size distribution does not change with respect to subsurface elevation within the LCRB. The results indicate that the LCRB has been dominated by fine sand deposition throughout the Holocene period, and silt and clay sized fractions were bypassed through the system to be deposited offshore. A total volume of 74.6 km3 of sediment has accumulated in the basin since the time of the catastrophic floods 12,700 years ago. Sediment volume analysis was used to predict past fluvial sediment supply rates and sediment retention. The volume of sediment deposition from early to late Holocene time has decreased by a factor of 2.4. Sedimentation rates in the basin are estimated from a basin isopach of the Holocene fill and from an extrapolated sediment sea-level curve. Basin sedimentation rates ranged from 12. 6 mm/yr-1 for the early Holocene to 2. 5 mm/yr-1 for the late Holocene period. This factor of 5 decrease in the sedimentation rate also indicates that the Columbia River bypassed much of its fine grained fraction through to the marine environment during the mid-late Holocene.
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Callefo, Flávia 1983. "Análise tafonômica e paleoecológica de estruturas associadas a comunidades microbianas holocênicas e permianas." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287739.
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Orientador: Fresia Soledad Ricardi Torres BrancoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: Esteiras microbianas são estruturas organossedimentares laminadas, desenvolvidas a partir do acréscimo de lâminas de sedimentos aprisionados através do metabolismo de microrganismos, que induzem a precipitação de carbonato. Microbialitos são depósitos organossedimentares formados pela interação de microrganismos com sedimentos detríticos, através dos processos de trapeamento e aglutinação dos grãos e minerais. Esta pesquisa apresenta os resultados obtidos com o estudo tafonômico e paleoecológico de estruturas desenvolvidas por atividade de microrganismos, como estromatólitos, microbialitos e esteiras microbianas, com o intuito de comparar os resultados e traçar similaridades e diferenças nas relações ecológicas e ambientes de formação . Foram utilizados modelos recentes (Holoceno), como a Lagoa Salgada e Lagoa Pitanguinha, RJ, para compreender modelos fósseis (Permiano), afloramentos em Taguaí e Santa Rosa do Viterbo, SP. A metodologia se constituiu em análise de sedimentos associados, petrografia, análises composicionais (como MEV/EDS e Espectroscopia Raman) e estudo de campo. Foram levados em consideração os aspectos ambientais e biota contemporânea ao crescimento e desenvolvimento dos microbiais. As principais conclusões obtidas foram que os ambientes apresentam similaridades com relação a biota desenvolvida, bem como as relações ecológicas que estas mantinham com as comunidades microbianas responsáveis pelo desenvolvimento dos microbialitos e esteiras microbianas. O ambientes de crescimento das estruturas eram marinhos de águas rasas e hipersalinas, com o clima quente e alta taxa de evaporação. A alternância de eventos de tempestades e águas calmas, com posterior período de calmaria no qual foi possível o desenvolvimento de esteiras microbianas foram evidenciados no afloramento de Taguaí e na Lagoa Pitanguinha. Os microbialitos recentes da Lagoa Salgada sofreram maior influência de atividade de predação e herbivoria por parte de invertebrados, o que pode ter sido um fator relevante para a limitação do crescimento destas estruturas em comparação com aquelas existentes em Santa Rosa do Viterbo
Abstract: Microbial mats can be defined as laminated organosedimentary structures developed from the addition of laminaes of sediments trapped trough microorganisms metabolism, which leads to carbonate precipitation. Microbialites are organosedimentary deposits generated by the interation between microorganisms and detritic sediments through trapping and agglutination of minerals and grains play a key role. This research present the results of taphonomic and paleoecological studies from of structures developed by the activity of microorganisms such as microbialites, stromatolites and microbial mats aiming to comparison between the results obtained and to map similarities and differences on the ecological relations and formation environments. Recent models such as Salgada Lagoon and Pitanguinha Lagoon (Holocene), both located on Rio de Janeiro, were used to understand permian fossils models, outcrops located in Taguaí and Santa Rosa do Viterbo/SP. The methodology was based on the analysis of associated sediments, petrography and compositional analysis (MEV/EDS and Raman Spectroscopy) besides field studies. Aspects such as recent environments and biotas were considered to the analysis. The main conclusions were that the environments present similarities based on the development of the biotas as well as the ecological relations which those developed within the microbial communities responsible for the development of the microbialites and microbial mats. The growth environments of the structures were classified as shallow marine hypersaline waters, with warm weather and high evaporation rates. There was an alternation between storm events and calm waters. The growth of microbial mats became possible when the waters were predominantly calm evidenced by the outcrops from Taguaí and Pitanguinha Lagoon. The recent microbialites from Salgada Lagoon had a greater influence by activities from predators and herbivorous organisms such as invertebrates, which may be a relevant factor for the limitation growth of these structures when compared with those founded at Santa Rosa do Viterbo
Mestrado
Geologia e Recursos Naturais
Mestra em Geociências
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Stine, Cynthia Marie. "Stratigraphy of the Ohanapecosh Formation north of Hamilton Buttes, southcentral Washington." PDXScholar, 1987. https://pdxscholar.library.pdx.edu/open_access_etds/3762.
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Over 1055 m of early Oligocene andesitic-dacitic volcaniclastic rocks and minor interbedded andesitic lava flows of the Ohanapecosh Formation are exposed in a dissected structural high in the southern Washington Cascade Range, about 22 km southwest of Packwood, Washington.
The exposed sequence of rocks in the study area are located approximately 250 m above the base of the Ohanapecosh Formation. A lower sequence of deposits, about 350 m in thickness, are dominated by primary and reworked lithic lapilli-tuff and epiclastic channelized volcanic sandstone and conglomerate. These sediments are interpreted as pyroclastic flows and stream deposits, respectively. The upper sequence, about 455 m thick is dominated by volcanic diamictites interpreted as lahars, with minor lithic lapilli-tuff and epiclastic volcanic sandstone.
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McDermid, Isabella Rose Cross. "Zedong Terrane, South Tibet." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31244610.
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Van, Lente Belinda. "Chemostratigraphic trends and provenance of the Permian Tanqua and Laingsburg depocentres, southwestern Karoo Basin, South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16075.
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Thesis (PhD)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: Foreland basins commonly fill with sediment derived from the adjacent fold/thrust belt, providing a relatively simple source-to-basin configuration. However, that is not true for the early southwestern Karoo Basin, since the composition of the Ecca Group sedimentary rocks do not match the composition of the adjacent fold/thrust belt. The southwestern Karoo Basin is bordered to the west and south by the Cape Fold Belt (CFB) and provides the opportunity to study the linkage between its early structural evolution and deposition in the two spatially and temporally distinct Tanqua and Laingsburg depocentres. The CFB was formed when the early Palaeozoic passive continental margin, which formed a large section of the southern edge of Gondwana, evolved into an active convergent margin during the late Palaeozoic. Orogenesis resulted in a northwest-trending Cedarberg branch and an eastwest-trending Swartberg branch. The oroclinal bend between the two branches includes large-scale northeast-trending syntaxis structures, such as the Hex River and Baviaanshoek anticlinoria, which influenced the sedimentation path into the basin. Spectral gamma ray (SGR), mineralogical and geochemical studies of exposed rocks from the Tanqua and Laingsburg depocentres indicate a near uniform provenance for both, dominated by granitic and metamorphic material derived from a provenance seemingly far beyond the CFB. SGR data, combined with lithology, show that regional stratigraphic correlation is possible in the Skoorsteenberg, Kookfontein and Waterford Formations in the Tanqua depocentre. The same is true for the Laingsburg and Fort Brown Formations in the Laingsburg depocentre. There are no major changes in the SGR data set between the successive sandstone or shale units that could imply different origin, and no distinct signals in the SGR pattern of the shale intervals that could potentially correspond to maximum flooding surfaces. The Tanqua and Laingsburg depocentre sandstones are very fine- to lower mediumgrained, tightly packed, poorly to well sorted, and have undergone mechanical compaction and pressure solution. The mineralogical composition and texture of these sandstones suggest that they have undergone high-grade diagenesis to low-grade regional burial metamorphism to the lower greenschist facies (250 ± 50ºC; ~2 kbars). They are mineralogically and geochemically classified as lithic arenites and greywackes, and the Tanqua depocentre sandstones are slightly more mature than the Laingsburg depocentresandstones. REE patterns for the Tanqua and Laingsburg depocentre sandstones are similar, suggesting that both form part of the same evolutionary pattern and that the sediments have one common origin, i.e. a provenance predominantly composed of granitic material. Homogenous εNd-values for all sandstone samples of around –5 at the time of deposition indicate that there is little or no variation in provenance between the Tanqua and Laingsburg depocentre sediments. TCHUR model ages of 0.70 to 0.95 Ga, and TDM model ages of 1.19 to 1.49 Ga, resulted from a mixture of Archaean and Proterozoic material in unknown proportions. The most likely source terrane is thought to be the North Patagonian Massif. The latter show Nd isotopic compositions corresponding to an average εNd-value of -5 at 265 Ma.
AFRIKAANSE OPSOMMING: Voorlandkomme word oor die algemeen gevul met sediment afkomstig van die aanliggende plooigordel, wat lei tot ‘n redelik eenvoudige brongebied-tot-afsettingskom konfigurasie. Dit is egter nie van toepassing vir die vroeë suidwestelike Karookom nie, aangesien die samestelling van die Ecca Groep sedimentêre gesteentes nie ooreenstem met die samestelling van die aanliggende plooigordel nie. Die suidwestelike Karookom word aan die weste en suide begrens deur die Kaapse Plooigordel en bied die geleentheid om die verwantskap tussen die vroeë strukturele evolusie en afsetting in die twee ruimtelik en temporeel afsonderlike Tankwa en Laingsburg subkomme te bestudeer. Die Kaapse Plooigordel het gevorm toe die vroeë Palaeosoïkum kontinentale grens, wat ‘n groot deel van die suidelike grens van Gondwana was, ontwikkel het tot ‘n aktiewe konvergerende grens gedurende die laat Palaeosoïkum. Orogenese het gelei tot die vorming van ‘n noordwes-strekkende Sederberg tak en ‘n ooswes-strekkende Swartberg tak. Die oroklinale buig tussen die twee takke sluit grootskaalse noordoosstrekkende sintaksis strukture in, soos die Hex Rivier en Baviaanshoek antiklinoria, wat die sedimentasie rigtings na die kom beïnvloed het. Spektrale gammastraal (SGR), mineralogiese en geochemiese studies op die dagsome van die Tankwa en Laingsburg subkomme dui ‘n byna identiese brongebied aan vir beide, oorheers deur granitiese en metamorfe materiaal vanaf ‘n brongebied oënskynlik vêr vanaf die Kaapse Plooigordel. SGR data, gekombineer met litologie, dui aan dat dit moontlik is om regionale stratigrafiese korrelasies in the Skoorsteenberg, Kookfontein en Waterford Formasies in die Tankwa subkom te maak. Dieselfde geld vir die Laingsburg en Fort Brown Formasies in die Laingsburg subkom. Daar is geen groot veranderinge, wat ‘n verskil in oorsprong kan aandui, in the SGR datastel tussen die opeenvolgende sandsteen of skalie eenhede nie, en ook geenuitstaande tekens in the SGR patroon van die skalie-intervalle wat moontlik kan ooreenstem met ‘n maksimum vloedingsvlak nie. Die Tankwa en Laingsburg subkom sandsteenlae is baie fyn- tot laervlak mediumkorrelrig, dig gekompakteer, swak tot goed gesorteer, en het meganiese kompaksie en drukoplossing ondergaan. Die mineralogiese samestelling en tekstuur van hierdie sandsteenlae dui daarop dat hulle hoë-graadse diagenese tot lae-graadse regionale begrawingsmetamorfose tot laervlak groenskis fasies (250 ± 50ºC; ~2 kbars) ondergaan het. Hulle word mineralogies en geochemies geklassifiseer as litiese areniete en grouwakke. Die Tankwa subkom sandsteenlae is effens meer volwasse as die Laingsburg subkom sandsteenlae. Die lantanietgroep patroon vir die Tanqua en Laingsburg sandsteenlae is eenders, wat aandui dat beide deel gevorm het van dieselfde evolusionêre ontwikkeling en dat die sedimente een gesamentlike oorsprong gehad het, naamlik ‘n brongebied bestaande hoofsaaklik uit granitiese materiaal. Homogene εNd-waardes van ongeveer –5 by tye van afsetting vir al die sandsteen monsters dui daarop dat daar min of geen verandering in brongebied vir die Tankwa en Laingsburg subkom sedimente was nie. TCHUR model ouderdomme van 0.70 tot 0.95 Ga, en TDM model ouderdomme van 1.19 tot 1.49 Ga, is afkomstig van ‘n mengsel van Argeïese en Proterosoïese materiaal in onbekende hoeveelhede. Die mees waarskynlike brongebied is die Noord Patagoniese Gebergtes. Dit wys Nd isotopiese samestellings wat ooreenstem met ‘n gemiddelde εNd-waarde van –5 by 265 Ma.
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Le, Roux F. G. "The lithostratigraphy of Cenozoic deposits along the south-east Cape coast as related to sea-level changes." Thesis, Stellenbosch : Stellenbosch University, 1989. http://hdl.handle.net/10019.1/67134.
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Thesis (MSc)--University of Stellenbosch, 1989.AFRIKAANSE OPSOMMING: Senosoiese sedimente langs die suidooskus van die Kaapprovinsie is periodiek deur verskeie outeurs vir meer as 'n eeu bestudeer. In hierdie aanbieding word die Iiteratuur saamgevat en vele dubbelsinnige stratigrafiese onderverdelings en definisies opgeklaar. Die Senosoiese afsettings kan volgens oorsprong geklassifiseer word as marien, eolies en fluviaal. Die mariene afsettings, synde strand-, nabystrand-, estuarien of lagunale afsettings geassosieerd met transgressiewe/ regressiewe kusIyne, word nou op grond van kenmerkende litologiese, paleontologiese sowel as ouderdomsverskille onderverdeel in die Paleogeen Bathurst, Neogeen Alexandria en Kwaternere Salnova Foraasies. Die Laat-Plioseen tot Vroeg-Pleistoseen Nanaga Formasie, Middel- tot Laat- Pleistoseen Nahoon Formasie en die Holoseen Schel• Hoek Formasie vorm die kus-eoliese afsettings. AI die mariene en marienverwante (eoliese} formasies, gekenmerk deur kalkige klastiese afsettings, is saamgegroepeer in 'n nuutgedefinieerde Algoa Groep. Fluviale afsettings word onderverdeel in die Martindale, Kinkelbos, Bluewater Bay, Kudus Kloof en Sunland Formasies. Die onderskeie afsettings word gekorreleer met verskillende seevlakstande deur geologiese tye. Die vroegste Senosoiese transgressiewe/regressiewe siklus het in die Vroeg-Paleoseen begin en die hoogste aangetekende elevasie vir die era bereik. Die Bathurst Formasie is waarskynlik gedurende hierdie regressie afgeset. 'n Tweed~ kleiner transgressie/ regressiesiklus het plaasgevind gedurende die Laat-Eoseen tot Vroeg-Oligoseen. Sover tans bekend, kan geen afsetting in die dagsoomgebied van die Algoa Groep definitief met hierdie siklus in verband gebring word nie. Die volgende siklus, wat 'n transgressiewe maksimum van c. 250 m bereik het, het begin in die Middel-Mioseen en verstryk in die Vroee Plioseen. Mariene planasie van die kusplatform het gedurende die transgressie plaasgevind terwyl die Alexandria Formasie wat tans bo 120 m geleë is, gedurende die regressie afgeset is. Die Vroeg-Plioseen transgressie het waarskynlik 'n maksimum huidige hoogte van c. 120 m bereik, waartydens o.a. die 120 m branderstoep en "Humansdorpterras" gekerf is. Die Alexandria Formasie tans geleë tussen 60 en 120 m, is afgeset gedurende die Laat-Plioseen regressie. Hierdie regressie het verskeie relatief lang stilstande, wat waarskynlik die 106-m, 90- tot 100-m en 84-m branderstoepe verklaar, ondervind. Selfs die 60-m en 52-m kuslyne kon tydens hierdie regressie gevorm het. Voorlopige paleontologiese getuienis dui egter daarop dat die 60-m kuslyn 'n transgressiewe maksimum van 'n daaropvolgende siklus verteenwoordig, gevolg deur 'n regressie met minstens een beduidende stilstand by 52 m. Die Alexandria Formasie geleë tussen c. 60 en 30 m, is waarskynlik gedurende hierdie regressie gedeponeer, waartydens ook die Bluewater Bay, Kinkelbos en Kudus Kloof Formasies afgeset is. Gedurende die Kwaternêre transgressie/regressiesiklusse, waarvan minstens vier aangedui word, is die Salnova Formasie (afwesig bo 30 m) afgeset. Die Nahoon Formasie, wat ook op groot skaal op die kontinentale bank ontwikkel is, is gedeponeer gedurende die laaste twee Pleistoseen glasiale toe seevlakke tot benede -100 m gedaal het. Die Schelm Hoek Formasie wat tans nog afgeset word, het ontstaan uit die transgressiewe maksimum van die Flandriese transgressie aan die begin van die Holoseen.
ENGLISH ABSTRACT: Cenozoic sediments along the south-east coast of the Cape Province have been studied intermittently for more than a century by various authors. In this presentation the literature is reviewed and many ambiguous stratigraphic subdivisions and definitions are clarified. The Cenozoic deposits can be classified, according to origin, as marine, aeolian and fluvial. The marine deposits, being lagoonal deposits either beach, nearshore, estuarine or associated with transgressive/regressive shorelines, are now subdivided on the grounds of distinct lithological, palaeontological as well as age differences into the Palaeogene Bathurst, Neogene Alexandria and Quaternary Salnova Formations. The Late Pliocene to Early Pleistocene Nanaga Formation, the Hiddle to Late Pleistocene Nahoon Formation and the Holocene Schelm Hoek Formation constitute the coastal and marine-related aeolian deposits. All the marine (aeolian) formations, which are characterised by calcareous clastics, have been grouped together in a newly defined Algoa Group. Fluvial deposits are subdivided into the Martindale, Kinkelbos, Bluewater Bay, Kudus Kloof and Sunland Formations. The various deposits are correlated with different stands of sea-level through geological time. The earliest Cenozoic transgression/regression cycle started in the Early Palaeocene and reached the highest recorded altitude for the era. The Bathurst Formation was probably deposited during this regression. A second lesser transgression/regression cycle occurred in the Late Eocene to Early Oligocene. As far as is presently known, no deposit in the outcrop area of the Algoa Group can be definitely related to this cycle. The next cycle, which reached a transgressive maximum of c. 250 m, started in the Middle Miocene and terminated in the Early Pliocene. Marine planation of the coastal platform took place during the transgression, whilst the Alexandria Formation presently situated above 120 m, was deposited during the regression. The Early Pliocene transgression is considered to have reached a maximum present-day elevation of c. 120 m, during which the 120 m marine bench and "Humansdorp Terrace", amongst others, were carved. The Alexandria Formation presently situated between 60 and 120 m, was deposited during the Late Pliocene regression, which experienced several relatively long stillstands which probably account for the 106 m, 90 t.o 100 m and 8.4 m benches. Even the 60 m- and 52 m-shorelines could have been formed during this regression. Preliminary palaeontological evidence, however, suggests that the 60 m shoreline represents a transgressive maximum of a subsequent cycle followed by a regression with at least one significant stillstand at 52 m. The Alexandria Formation situated between c. 60 and 30 m, was probably deposited during this regression, which also saw the deposition of the Bluewater Bay, Kinkelbos and Kudus Kloof Formations. During the Quaternary transgression/regression cycles, of which at least four are indicated, the Salnova Formation (absent above 30 m) was deposited. The Nahoon Formation, which is also extensively developed on the continental shelf, was deposited during the last two Pleistocene glacials, when sea-levels receded to less than -100 m. The Schelm Hoek Formation, which is still being deposited, originated from the transgressive maximum of the Flandrian transgression at the start of the Holocene.
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Megner-Allogo, Alain-Cedrique. "Sedimentology and stratigraphy of deep-water reservoirs in the 9A to 14A Sequences of the central Bredasdorp Basin, offshore South Africa." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/17400.
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Thesis (MSc)--University of Stellenbosch, 2006.ENGLISH ABSTRACT: The Barremian to Albian siliciclastic deep-water deposits of the central Bredasdorp Basin were investigated primarily in terms of their stratigraphic evolution, depositional characteristics and facies distribution. Cores from the deep-water deposits reveal that the facies successions are composed of massive, ripple cross- to parallel-laminated sandstones, conglomerate, massive claystone, alternating laminated to interbedded sandstone/siltstone and claystone, laminated and clay-rich siltstone. These facies are grouped into channel-fill, sheet-lobe, overbank and basin plain deposits, by inference. The application of sequence stratigraphy, based on gamma ray and resistivity log patterns, reveals that all 3rd-order depositional sequences comprise 4thorder cycles. The latter are subdivided into three components (lowstand, transgressive and highstand systems tracts), based on vertical facies changes and internal stratigraphic key surfaces. Taking the 13Amfs as the stratigraphic datum for each well, correlation was possible on a regional basis. Lowstand deposits, comprising thick amalgamated massive sandstones, were interpreted to represent channelfills. Their vertical and horizontal stacking forms channel-fill complexes above Type 1 unconformities. Adjacent thin-bedded intervals, comprising parallel- to ripple cross-laminated sandstones, were interpreted as levee/overbank deposits, whereas clay-rich intervals were interpreted to represent basin plain deposits of hemipelagic origin. Facies associations and their distribution have revealed that channel-fills are associated with overflow deposits and sheet sand units. These deposits, as well as downdip sheet sands associated with small channel-fills within the 9A, 11A/12A, 13A Sequences and the 14A Sequence were interpreted to have been deposited in a middle fan to upper fan setting. A similar association occurs in the 10A Sequence, except that thick conglomerate units are present at the base of proximal channel-fills. This led to interpret the 10A Sequence as being deposited in a base-of-slope to upper fan setting. The thickness of each sequence, as revealed by isochore maps, shows sinuous axial flow path which corresponds to channel-fill conduit. The continuous decrease of this sinuosity upward in the succession was interpreted as being related to basin floor control along the main sand fairways. Successive flows result in erosion-fill-spill processes, which locally favour connectivity of reservoirs over large areas. Recognition of higher-order sequences and key stratigraphic surfaces helps to understand internal stratigraphic relationships and reveals a complex and dynamic depositional history for 3rd-order sequences. However, sparse well control and uneven distribution of boreholes, as well as lack of seismic and other data, limited the models derived for this study.
AFRIKAANSE OPSOMMING: Die Barremiaanse tot Albiaanse silisiklastiese diepwater afsettings van die sentrale Bredasdorp Kom is hoofsaaklik in terme van stratigrafiese evolusie, afsettingskarakteristieke en fasies distribusie ondersoek. Kerne van die diepwater afsettings toon dat die fasies opeenvolgings uit massiewe, riffelkruis- tot parallel-gelamineerde sandstene, konglomerate, massiewe kleistene, afwisselende gelamineerde tot intergelaagde sandstene/slikstene en kleistene, sowel as gelamineerde en klei-ryke slikstene bestaan. Hierdie fasies word onderverdeel in kanaalopvulsel, plaatlob, oewerwal en komvlakte afsettings. Die toepassing van opeenvolgingsstratigrafie gebaseer op gammastraal en resistiwiteit log patrone toon dat alle 3de-orde afsettingsopeenvolgings uit 4deorde siklusse bestaan. Laasgenoemde word onderverdeel in drie komponente (lae-stand, transgressie en hoë-stand sisteemgedeeltes), gebaseer op vertikale fasies veranderinge en interne stratigrafiese sleutel vlakke. Korrelasie op ‘n regionale basis is moontlik gemaak deur die 13Amfs as die stratigrafiese verwysing vir elke boorgat te neem. Lae-stand afsettings, wat uit dik saamgevoegde massiewe sandstene bestaan, word geïnterpreteer as kanaalopvulsels. Die vertikale en horisontale stapeling van die sandstene vorm kanaalopvulsel komplekse bo Tipe 1 diskordansies. Naasliggende dungelaagde intervalle, wat uit parallel- tot kruisgelaagde sandstene bestaan, word geïnterpreteer as oewerwal afsettings, terwyl klei-ryke intervalle geïnterpreteer word as verteenwoordigend van komvlakte afsettings van hemipelagiese oorsprong. Fasies assosiasies en hul verspreiding toon dat kanaalvul geassosieër word met oorvloei afsettings en plaatsand eenhede. Hierdie afsettings, sowel as distale plaatsande geassosieër met klein kanaalopvulsels binne die 9A, 11A/12A, 13A en die 14A Opeenvolgings, word geïnterpreteer as afgeset in ‘n middelwaaier tot bo-waaier omgewing. ‘n Soortgelyke assosiasie bestaan in die 10A Opeenvolging, behalwe dat dik konglomeraat eenhede teenwoordig is by die basis van proksimale kanaalopvullings. Dit het gelei tot die interpretasie van die 10A Opeenvolging as afgeset in ‘n basis-van-helling tot bo-waaier omgewing. Die dikte van elke opeenvolging, soos verkry vanaf isochoor kaarte, toon ‘n kronkelende aksiale vloeipad wat ooreenkom met ‘n kanaalopvulling toevoerkanaal. Die aaneenlopende afname van hierdie kronkeling na bo in die opeenvolging word geïnterpreteer as verwant aan komvloer-beheer langs die hoof sand roetes. Opeenvolgende vloeie veroorsaak erosie-opvul-oorspoel prosesse, wat lokaal die konnektiwiteit van reservoirs oor groot areas bevoordeel. Herkenning van hoër-orde opeenvolgings en sleutel stratigrafiese vlakke dra by tot ‘n goeie begrip van die interne stratigrafiese verhoudings en ontbloot ‘n komplekse en dinamiese afsettingsgeskiedenis vir 3de-orde opeenvolgings. Beperkte boorgatbeheer en ‘n tekort aan seismiese en ander data het egter ‘n beperkende rol gespeel in die daarstel van modelle vir hierdie studie.
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Alao, Abosede Olubukunola. "Basinfill of The Permian Tanqua depocentre, SW Karoo basin, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20277.
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Thesis (MSc)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Basin subsidence analysis, employing the backstripping method, indicates that fundamentally two different basin-generating mechanisms controlled Tanqua depocentre development in SW Karoo Basin. The subsidence curves display initial dominantly decelerating subsidence, suggesting an extensional and thermal control possibly in a strikeslip setting during the depocentre formation; on the other hand, subsequent accelerating subsidence with time suggests that the dominant control on the depocentre formation in SW Karoo was flexure of the lithosphere. Based on these observations on the subsidence curves, it is possible to infer that the first stage of positive inflexion (~ 290 Ma) is therefore recognised as the first stage of Tanqua depocentre formation. Petrographic study show that most of the studied sandstones of the Tanqua depocentre at depth of ~ 7.5 Km were subjected to high pressure due to the overlying sediments. They are tightly-packed as a result of grains adjustment made under such pressure which led also to the development of sutured contacts. It is clear the high compaction i.e. grain deformation and pressure solution occurred on the sediments; leading to total intergranular porosity reduction of the quartz-rich sediments and dissolution of the mineral grains at intergranular contacts under non-hydrostatic stress and subsequent re-precipitation in pore spaces. Furthermore, siliciclastic cover in the Tanqua depocentre expanded from minimal values in the early Triassic (Early to Late Anisian) and to a maximum in the middle Permian (Wordian -Roadian); thereby accompanying a global falling trend in eustatic sea-level and favoured by a compressional phase involving a regional shortening due to orogenic thrusting and positive inflexions (denoting foreland basin formation). The estimate of sediment volume obtained in this study for the Permian Period to a maximum in the middle Permian is therefore consistent with published eustatic sea-level and stress regime data. In addition, this new data are consistent with a diachronous cessation of marine incursion and closure of Tanqua depocentre, related to a compressional stress regime in Gondwana interior during the late Palaeozoic.
AFRIKAANSE OPSOMMING: Die ontleding van komversakking met behulp van die terugstropingsmetode bring aan die lig dat die ontwikkeling van die Tankwa-afsettingsentrum in die Suidwes-Karoo-kom hoofsaaklik deur twee verskillende komvormende meganismes bepaal is. Die versakkingskurwes toon aanvanklike, hoofsaaklik verlangsaamde versakking, wat daarop dui dat ekstensie- en termiese beheer gedurende die vorming van die afsettingsentrum plaasgevind het, waarskynlik in strekkingwaartse opset. Aan die ander kant toon daaropvolgende versnellende versakking wat mettertyd plaasgevind het dat die vorming van die afsettingsentrum in die Suidwes-Karoo eerder oorwegend deur kromming van die litosfeer beheer is. Op grond van hierdie waarnemings met betrekking tot die versakkingskurwes, kan mens aflei dat die eerste stadium van positiewe infleksie (~ 290 Ma) dus as die eerste stadium van die vorming van die Tankwa-afsettingsentrum beskou kan word. Petrografiese studie toon dat die meeste van die sandsteen wat van die Tankwaafsettingsentrum bestudeer is, op diepte van ~ 7,5 Km aan hoë druk onderwerp was weens die oorliggende sedimente. Die sandsteen is dig opmekaar as gevolg van die korrelaanpassing wat onder sulke hoë druk plaasvind, wat op sy beurt ook tot die ontwikkeling van kartelnaatkontakte aanleiding gegee het. Dit is duidelik dat die sediment aan hoë verdigting, dit wil sê korrelvervorming en drukoplossing, onderwerp was, wat gelei het tot algehele afname in interkorrelporeusheid by die kwartsryke sedimente; die ontbinding van die mineraalkorrels in interkorrelkontaksones onder niehidrostatiese spanning, en daaropvolgende herpresipitasie in poreuse ruimtes. Voorts het silisiklastiese dekking in die Tankwa-afsettingsentrum toegeneem van minimale waardes in die vroeë Triassiese tydperk (vroeë tot laat Anisiaanse tydperk) tot hoogtepunt in die mid-Permiaanse tydperk (Wordiaans–Roadiaans). Dié ontwikkeling het gepaardgegaan met algemene dalingstendens in die eustatiese seevlak, en is verder aangehelp deur saamdrukkingsfase wat gekenmerk is deur regionale verkorting weens orogeniese druk en positiewe infleksies (wat met voorlandkomvorming saamhang). Die geraamde sedimentvolume wat in hierdie studie vir die Permiaanse tydperk bepaal is, met die hoogtepunt in die middel van dié tydperk, is dus in pas met gepubliseerde data oor die eustatiese seevlak en spanningstoestand. Daarbenewens strook hierdie nuwe data met diachroniese staking van mariene instroming en die afsluiting van die Tankwaafsettingsentrum wat met spanningstoestand in die Gondwana-binneland gedurende die laat Paleosoïkum verband hou.
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Van, der Merwe Willem C. "Stratigraphy and facies architecture of the uppermost fan system in the Tanqua sub-basin, Permian Ecca Group, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50454.
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Thesis (MSc)--Stellenbosch University, 2005.ENGLISH ABSTRACT: Fan System 5 forms the uppermost submarine fan system of the Permian-age Tanqua Fan Complex (Ecca Group) of the southwestern Karoo Basin. It is the most widespread system and represents the final phase of fan deposition in the Tanqua sub-basin. Depositional characteristics differ markedly from the rest of the fan systems, mainly because it lacks sedimentary features indicative of a single point source basin floor fan. The entire system consists of six different stages of fan growth and development in the lower slope settings. A hypothetical model was composed for Fan System 5 to understand the spatial/temporal distribution of reservoir and seal facies in slope turbidite settings. The facies vary from massive amalgamated sandstone beds to thin-bedded, ripple cross-laminated sand and siltstone beds. A thick shale unit identified as a regional marker layer overlies Fan System 5. lts base is defined by the presence of a regionally developed 20 cm thick hemipelagic shale unit. Six sand-rich units with channel-complexes are present in the Klein Hangklip, Groot Hangklip, Kalkgat, Tongberg, Skoorsteenberg and Blauwkop localities. The facies characteristics in the southernmost outcrops of Fan System 5 (Groot Hangklip, Tongberg and Kalkgat) reflect deposition in a lower slope setting where local structural control seems to have played a major role in the distribution and regional development of channel-fill and overbank depositional elements. The channel-fills are arranged in vertical to off-set stacking patterns and are comprised of massive, amalgamated [me to very fine-grained sandstone units up to 30 m in thickness. They are separated by thinner sandstone/siltstone units of varying thickness. The channelization displayed by the more proximal outcrops are interpreted to represent an upper fan, deposited in a lower- to mid-slope setting. In contrast to the channel-fill deposits at Skoorsteenberg, Klein Hangklip and Groot Hangklip, ripple cross-laminated overbank deposits, associated with smaller channel-fill units, predominate in the northeastern and eastern parts of the outcrop area. Massive- and thinbedded frontal sheet sandstones constitute the down-dip extensions to the most northern outcrops of Fan System 5. Highly erosive, stacked base-of-slope channel complexes, seemingly controlled by subtle early structural features, were able to construct significant thicknesses of regionally well-developed overbank deposits, marginal to the channel complexes. These facies changes occur over relatively short distances, which hold significant implications for the prediction of and the heterogeneity of reservoir facies in slope settings. Gradients are much steeper in the lower slope to mid-slope area than on the proximal basin floor. The occurrence of soft-sediment deformation in the overbank and upper parts of the channel-fill deposits supports a slope origin. Weakly developed wave-ripple marks in the uppermost layers of Fan System 5 further indicate that water depths approached wave base prior to deposition of the upper markerbed shales. Paleotransport for Fan System 5 was towards the north, northeast and east. The palaeocurrent directions of the channel-fill complexes in Klein- and Groot Hangklip seem to roughly correspond to the structural trend of synclinal depressions in this area. However, the effect and influences of basin floor topography and structural features on deposition were determined to be minimal on the regional development and local facies control of the fan.
AFRIKAANSE OPSOMMING: Waaiersisteem 5 vorm die laaste submarine waaiersisteem van die Perm-ouderdom Tankwa Waaierkompleks (Ecca Groep) in die suidwestelike Karoo-kom. Dit vorm die mees wydverspreide sisteem en verteenwoordig ook die fmale fase van waaierafsetting in die Tankwa sub-kom. Afsettingseienskappe verskil aansienlik van die onderliggende waaiersisteme, omdat kenmerkende sedimentêre eienskappe van 'n enkele toevoer bron ontbreek. Die hele sisteem bestaan uit ses verskillende periodes van waaiergroei en ontwikkeling in die laer kornhelling omgewmgs. 'n Voorspellingsmodel is opgestel vir Waaiersisteem 5 om die ruimtelike/temporele verspreiding van die reservoir en seël fasies in kornhelling turbidiet omgewings te kan verstaan. Hierdie fasies varieer van massiewe, geamalgameerde sandsteen tot dun gelaagde riffel- lamineerde sand- en sliksteenlae. 'n Dik regionale skalie eenheid oorlê Waaiersisteem 5 en vorm die boonste merkerlaag. Die basis word onderlê deur 'n 20 cm dik regionaalontwikkelde hemipelagiese skalie laag wat die onderste merkerlaag vorm. Ses sandige eenhede met geassosieerde kanaalkomplekse is onderskeidelik teenwoordig in: Klein Hangklip, Groot Hangklip, Kalkgat, Tongberg, Skoorsteenberg en Blauwkop omgewings. Die fasies-eienskappe van die mees suidelike dagsome van Waaiersisteem 5 (Tongberg, Groot Hangklip en Kalkgat) toon afsetting in 'n laer kornhelling omgewing, waar plaaslike tektoniese effekte moontlik 'n groot rol gespeel het in die verspreiding en regionale ontwikkeling van die kanaalvulsels en geassosieerde oewerwal-afsettings. Die gestapelde, wegstand kanaalvulsels-afsettings bestaan uit massiewe, geamalgameerde fyn tot baie fynkorrelrige sandsteen eenhede, wat diktes tot ongeveer 30 m kan bereik. Dit word van mekaar geskei deur dun sandsteenlsliksteen eenhede van afwisselende diktes. Die kanaal komplekse in die mees proksimale dagsome word interpreteer as 'n bo-waaier, wat afgeset is in 'n laer- tot middel kornhelling omgewmg. In teenstelling met die kanaalvulsels in die Skoorsteenberg, Klein Hangklip en Groot Hangklip omgewings, domineer riffel kruisgelamineerde oewerwal-afsettings, geassoseer met klein kanaalvulsels, die noordoostelike en oostelike dagsome van Waaiersisteem 5. Massiewe en dungelaagde frontale plaat sandstene, kom voor in die distale helling-omgewings in die mees noordelike dagsome van Waaiersisteem 5. Hoogs eroderende, gestapelde kanaalkomplekse, aan die basis van die komhelling wat moontlik beheer is deur vroeë komvloer topografie, was die oorsaak vir regionaal goed-ontwikkelde oewerwalafsettings. Hierdie fasies-verandering vind plaas oor 'n baie kort afstand wat betekenisvolle gevolge inhou vir die voorspelling van heterogeniteit van petroleum reservoir fasies in komhelling afsetting-omgewings. Die gradiënt vir die laer komhelling tot mid-komhelling omgewings is baie steiler as die distale komvloer omgewings. Die voorkoms van sagte-sediment deformasies in die oewerwal en boliggende dele van die kanaalvulsels weerspeël 'n moontlike komhelling omgewing. Swakontwikkelde golfriffelmerke in die boonste lae van Waaiersisteem 5 dui 'n waterdiepte aan wat nabyaan golf-basis is, voordat dit deur diepmariene skalies oorlê word. Paleovloeirigtings vir Waaiersisteem 5 was in 'n noord, noordoostelike en oostelike rigting. Die paleovloeirigting vir die Klein- en Groot Hangklip kanaalkomplekse stem min of meer ooreen met die strukturele grein van die sinklinale laagtes in die omgewing. Die effek en beheer van komvloer topografie en ander strukturele faktore op afsetting was minimaalop die regionale ontwikkeling en plaaslike fasies verspreiding van die waaier.
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Krentz, Sarah. "Potentially tsunamigenic event layer in late Holocene Great South Bay, Long Island, New York constraints on origins, processes, and effects /." Diss., 2009. http://etd.library.vanderbilt.edu/available/etd-07232009-175830/.
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Escalona, Alejandro. "Regional tectonics, sequence stratigraphy and reservoir properties of Eocene clastic sedimentation, Maracaibo Basin, Venezuela." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3119517.
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Combellas, Bigott Ricardo Ignacio. "Depositional and structural evolution of the middle Miocene depositional episode, east-central Gulf of Mexico /." 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3117894.
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Wu, Xinxia Galloway William E. "Upper Miocene depositional history of the Central Gulf of Mexico basin." 2004. http://repositories.lib.utexas.edu/bitstream/handle/2152/2091/wux042.pdf.
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Combellas, Bigott Ricardo Ignacio Galloway William E. "Depositional and structural evolution of the middle Miocene depositional episode, east-central Gulf of Mexico." 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3117894.
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Bisby, Curtis G. "Depositional environments of the Wood Siding Formation and the Onaga Shale (Pennsylvanian-Permian) in northeast Kansas." 1986. http://hdl.handle.net/2097/27595.
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Moothart, Steve Rene'. "Geology of the middle and upper Eocene McIntosh Formation and adjacent volcanic and sedimentary rock units, Willapa Hills, Pacific County, southwest Washington /." 1992. http://hdl.handle.net/1957/12293.
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Thesis (M.S.)--Oregon State University, 1993.Includes mounted photographs. Three folded plates in pocket. Typescript (photocopy). Includes bibliographical references (leaves 213-225). Also available on the World Wide Web.
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"The reconstruction of late quaternary depositional environments in the vicinity of Yuen Long." Chinese University of Hong Kong, 1996. http://library.cuhk.edu.hk/record=b5888963.
Full textAbstract:
by Cheung May Shuen.Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.
Includes bibliographical references (leaves 157-165).
ABSTRACT --- p.i
ACKNOWLEDGEMENTS --- p.ii
LIST OF FIGURES --- p.vi-ix
LIST OF PLATES --- p.x
LIST OF TABLES --- p.xi
Chapter CHAPTER I - --- INTRODUCTION
Chapter 1.1 --- Background of Quaternary Studies in Hong Kong --- p.1
Chapter 1.2 --- The Necessity of Regional and Local Practice --- p.3
Chapter 1.3 --- The Need for Regional Synthesis --- p.6
Chapter 1.4 --- Linking Onshore Studies with Offshore Ones --- p.8
Chapter 1.5 --- The Yuen Long Floodplain --- p.10
Chapter 1.5.1 --- Previous Work --- p.10
Chapter 1.5.2 --- The Need for Detailed Study --- p.12
Chapter 1.6 --- Objectives of the Study --- p.13
Chapter 1.7 --- Significance of the Study --- p.14
Chapter CHAPTER II - --- LITERATURE REVIEW
Chapter 2.1 --- Introduction --- p.17
Chapter 2.2 --- The Quaternary Period --- p.18
Chapter 2.3 --- Global Pleistocene Sea-level Reduction --- p.19
Chapter 2.4 --- Evidence of Pleistocene Sea-level Reduction in South China and Hong Kong --- p.20
Chapter 2.5 --- The Postglacial Rise in Sea-level --- p.22
Chapter 2.6 --- Holocene Sea-level Movements in Zhujiang Delta and Hong Kong --- p.23
Chapter 2.7 --- Hong Kong Quaternary Studies --- p.26
Chapter 2.7.1 --- A Wealth of Offshore Studies --- p.26
Chapter 2.7.2 --- A Lack of Onshore Studies --- p.27
Chapter 2.8 --- Methods of Investigation --- p.28
Chapter 2.9 --- Offshore Quaternary Sediments in Hong Kong --- p.30
Chapter 2.9.1 --- The Chek Lap Kok Formation --- p.31
Age of Formation --- p.32
Seismic Characteristics --- p.33
Lithology --- p.33
Sedimentary Environment --- p.34
Chapter 2.9.2 --- The Sham Wat Formation --- p.36
Age of Formation --- p.36
Seismic Characteristics --- p.37
Lithology --- p.37
Sedimentary Environment --- p.38
Chapter 2.9.3 --- The Hang Hau Formation --- p.39
Age of Formation --- p.39
Seismic Characteristics --- p.40
Lithology --- p.40
Sedimentary Environment --- p.41
Chapter 2.10 --- Summary of Hong Kong Quaternary Superficial Geology --- p.42
Chapter CHAPTER III - --- STUDY AREA
Chapter 3.1 --- Introduction --- p.44
Chapter 3.2 --- Geographical Setting and Existing Development --- p.45
Chapter 3.3 --- Relief --- p.47
Chapter 3.4 --- Climate --- p.47
Chapter 3.5 --- Surface Hydrology --- p.51
Chapter 3.6 --- Geology --- p.51
Chapter 3.7 --- Geomorphology --- p.53
Chapter 3.8 --- Superficial Deposits --- p.55
Chapter 3.9 --- The Hong Kong Geological Survey --- p.58
Chapter 3.10 --- Location of Boreholes BGS 11 and 23 --- p.58
Chapter CHAPTER IV - --- METHODOLOGY
Chapter 4.1 --- Introduction --- p.61
Chapter 4.2 --- Borehole Collection --- p.61
Chapter 4.3 --- Analytical Approach --- p.62
Chapter 4.4 --- Laboratory Logging and Description --- p.64
Chapter 4.5 --- Sedimentological Analysis --- p.65
Chapter 4.6 --- Geochemical Analysis --- p.66
Chapter 4.7 --- Micropalaeontological Analysis --- p.71
Chapter 4.8 --- Chronological Analysis --- p.73
Chapter 4.9 --- Stratigraphy and Borehole Comparison --- p.74
Chapter CHAPTER V - --- BGS 11 - DESCRIPTION AND DISCUSSION
Chapter 5.1 --- Introduction --- p.75
Chapter 5.2 --- Geological Description of Borehole BGS 11 --- p.76
Chapter 5.3 --- Geochemical Results --- p.90
Chapter 5.3.1 --- Soil Reaction pH --- p.91
Chapter 5.3.2 --- Electrical Conductivity --- p.91
Chapter 5.3.3 --- Organic Carbon --- p.93
Chapter 5.3.4 --- Calcium Carbonates --- p.93
Chapter 5.4 --- Micropalaeontological Results --- p.94
Chapter 5.4.1 --- Diatom Results --- p.94
Chapter 5.4.2 --- Sponge Spicules Results --- p.98
Chapter 5.5 --- Radiocarbon Dating Results --- p.100
Chapter 5.6 --- Environmental Interpretations --- p.101
Chapter 5.6.1 --- The Terrestrial Sequence (20.70 to 8.10m) --- p.101
The Colluvial Unit (20.70 to 16.50m) --- p.102
The Floodplain Unit (16.50 to 8.10m) --- p.103
The Palaeosol Unit (8.10 to 7.26m) --- p.107
Chapter 5.6.2 --- The Shallow Marine Sequence (7.26 to 4.05m) --- p.108
Chapter 5.6.3 --- The Coastal Swamp Sequence (4.05 to 2.35m) --- p.111
Chapter 5.7 --- Conclusion --- p.113
Chapter CHAPTER VI - --- BGS 23 - DESCRIPTION AND DISCUSSION
Chapter 6.1 --- Introduction --- p.114
Chapter 6.2 --- Geological Description of Borehole BGS 23 --- p.114
Chapter 6.3 --- Geochemical Results --- p.126
Chapter 6.4 --- Micropalaeontological Results --- p.129
Chapter 6.5 --- Environmental Interpretation --- p.129
Chapter 6.5.1 --- The Weathered Shale Sequence (15.90 to 15.00m) --- p.130
Chapter 6.5.2 --- The Fluvial Sequence (13.65 to 2.85m) --- p.131
Chapter 6.5.3 --- The Backswamp Sequence (2.85 to 1.73m) --- p.135
Chapter 6.6 --- Conclusion --- p.137
Chapter CHAPTER VII - --- STRATIGRAPHICAL INTERPRETATION AND COMPARISON
Chapter 7.1 --- Introduction --- p.138
Chapter 7.2 --- Stratigraphical Division in Hong Kong and the Zhujiang Delta --- p.138
Chapter 7.3 --- Stratigraphical Interpretation of BGS 11 --- p.140
Chapter 7.4 --- Stratigraphical Interpretation of BGS 23 --- p.142
Chapter 7.5 --- Stratigraphic Comparison --- p.143
Chapter 7.5.1 --- Comparison with Onshore Boreholes --- p.143
Chapter 7.5.2 --- Comparison with Offshore Boreholes in Hong Kong and Zhujiang Delta --- p.147
Chapter 7.6 --- Conclusion --- p.150
Chapter CHAPTER VIII - --- SUMMARY AND CONCLUSION
Chapter 8.1 --- Summary of Findings --- p.151
Chapter 8.2 --- Limitations --- p.153
Chapter 8.3 --- Future Work --- p.155
REFERENCES --- p.157
APPENDICES
APPENDIX A The complete logging sheets for BGS11
APPENDIX B The complete logging sheets for BGS23
37
Myrow, Paul Michael. "Sedimentology and depositional history of the Chapel Island Formation (late Precambrian to early Cambrian) southeast Newfoundland /." 1987. http://collections.mun.ca/u?/theses,97100.
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Hiebert, Franz Kunkel. "The role of bacteria in the deposition and early diagenesis of the Posidonienschiefer, a Jurassic oil shale in southern Germany." 1988. http://repositories.lib.utexas.edu/bitstream/handle/2152/6770/txu-oclc-19531066[1].pdf.
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Wu, Xinxia. "Upper Miocene depositional history of the Central Gulf of Mexico basin." Thesis, 2004. http://hdl.handle.net/2152/2091.
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Combellas, Bigott Ricardo Ignacio 1974. "Depositional and structural evolution of the middle Miocene depositional episode, east-central Gulf of Mexico." 2003. http://hdl.handle.net/2152/12128.
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Cole, Edward George. "Lithostratigraphy and depositional environment of the Archaean Nsuze Group, Pongola Supergroup." Thesis, 2014. http://hdl.handle.net/10210/11447.
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Bermúdez, Santana Juan Clemente. "Sequence stratigraphy and depositional history of the upper Cañon del Tule, Las Imagenes, and Lower Cerro Grande Formations, central Parras Basin, northeastern Mexico." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3117827.
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Clendinin, C. W. "Tectonic influence on the evolution of the Early Proterozoic Transvaal sea, southern Africa." Thesis, 2015. http://hdl.handle.net/10539/16515.
Full textAbstract:
The epeiric Transvaal Sea covered the Kaapvaal Craton of
southern Africa during the Early Proterozoic and its remnant
strata represent one of the oldest known carbonate depositories.
A genetic stratigraphic approach has been used in this research
on the evolution and syndepositional tectonics of the Transvaal
Sea; research also emphasized the development of basement
precursors, which influenced the Transvaal Sea. Eight subfacies
were initially recognized and their interrelationships through
Transvaal Sea time and space were used to identify ten
depositional systems. Paleogeographic reconstructions indicate
that the depositional systems developed on morphological
variations of a distally-steepened carbonate rarp and that the
depositional character of each was simply a function of water
Backstripping of the depositional systems indicates that the
Transvaal Sea was compartmentalized; three compartments are
preserved on the Kaapvaal Craton. Backstripping also indicates
that the depositional center of the Transvaal Sea lay over the
western margin of an underlying rift. Rifting had developed a
major, north-south-trending structure, and its geographical
interrelationships with the east-west-trending Selati Trough
created the compartment architecture of the basement.
Interpretation of syndepositional tectonics suggests that
six stages of subsidence influenced the Transvaal Sea. Early
subsidence consisted of mechanical (rift) subsidence followed by
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Reinsborough, Brian C. 1961. "Sequence stratigraphy and depositional systems of the Paleocene Andrew Formation in the central North Sea : the evolution of a slope-to-basin system." 1993. http://hdl.handle.net/2152/20635.
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This study focuses on the main depocenter of the Andrew Formation in the Moray Firth Basin, located at the junction of the Central and Viking Grabens, in the central North Sea. The objectives of this report are to (1) define the sequence stratigraphic framework of the Andrew Formation, (2) describe and characterize the depositional systems associated to the Andrew slope to basin system, and (3) interpret the depositional processes that have dominated sediment emplacement. Specific facies association of the Andrew Formation are determined by the nature (point source or linear source) and caliber (volume, grain size, sand:mud) of sediment supply to the slope environment. Genetic interpretation of the Andrew Formation focuses on understanding depositional processes which dominated sediment emplacement. Seven depositional facies have been identified for the Andrew slope and basinal system; turbidite channel-fills, turbidite lobes, mounded turbidite lobes, sheet turbidites, debris flows and slumps, low density turbidites and hemipelagic drapes. Seven depositional processes collectively create the above mentioned Andrew depositional facies; turbidity currents, cohesive mud flows, sandy debris flows, muddy debris flows, slumping, low density turbidity currents and suspension settling. The Andrew Formation consists of upper and lower depositional units identified on seismic by bounding downlap terminations and on well logs by high-gamma marker beds. The lower Andrew displays three distinct sand-rich lobes, delineated by isopach and sand percent maps and log motif characteristics. Proximal, mounded, sand-rich units disperse into unchannelized sheet turbidites in the basin plain areas. The upper Andrew downlaps the lower unit, and a single, linear sediment source was centered in the Witch Ground Graben. The sediment dispersal pattern and internal facies character suggest the upper unit is a proximal slope-apron downlapping and filling inter-lobe bathymetric lows of the underlying unit. The lower Andrew is interpreted to be a structurally focused, sand-rich lobe complex, without associated incised canyons. The Andrew system evolved as the delta platform expanded onto the proximal fan, resulting in a linear sediment source spilling over the slope as a fringing slope-apron. The Andrew depositional system in the slope and basin environment is characterized by a high degree of facies disorganization composed of a wide array of gravity-flow deposits.text
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Forkner, Robert Murchison 1977. "Depositional periodicity and the hierarchy of stratigraphic forcing in the Triassic carbonates of the Dolomite Alps, N. Italy." Thesis, 2007. http://hdl.handle.net/2152/23400.
Full textAbstract:
The Dolomite Alps of northern Italy are a classic field locality in the development carbonate stratigraphic theory. Included in the many discoveries rooted in the geology of the Dolomites is the concept of a hierarchy of stratigraphic forcing in the Alpine Triassic. The hierarchy states that carbonate sedimentation is dominantly a record of eustasy, resulting in organized stacking patterns, and that these stacking patterns reflect the interplay between low frequency (1-10 my) eustatic cycles and their component bundled high-frequency (100 & 20 kyr) eustatic cycles. The overall aim of this study is to further investigate the validity of the hierarchical model after recent dating of Anisian and Ladinian successions called the Milankovitchian periodicity and/or allocyclicity of the cyclic series into question. The study was completed using four sub-studies, 3 based on data collected in the field and a fourth based in cycle theory and computer modeling. First, it can be shown that allocyclic forcing exists in the Anisian/Ladinian platforms of the Dolomites by comparing the stratigraphic sections measured from 2 time-equivalent, independent carbonate platforms, the Latemar and Mendola Pass. Second, computer modeling of Anisian/Ladinian carbonate platform stratigraphy using Milankovitchain solar insolation as a proxy for high-frequency eustasy shows that both pure Milankovitch forcing and mixed Milankovitch/sub-Milankovitch forcing will produce synthetic carbonate platforms with stratigraphic successions comparable to those of the Anisian/Ladinian platforms of the Dolomites. Third, it can be shown that the while the Norian Dolomia Principale (a regional carbonate shelf) was affected by differential subsidence, megacycles systematically increase in their number of component cycles from 2-3:1 in the eastern Dolomites (updip) to 5-6:1 in the western Dolomites (seaward). In conclusion, the concept that carbonate platform stratigraphy is a record of an interplay between eustasy, subsidence, and sedimentation is upheld, while the validity of Milankovitchian forcing acting on all Alpine carbonate cycles is questioned. Instead, cyclic carbonates with sub-Milankovitch periodicities were common in the early and mid-Triassic, while cycles with Milankovitchian periodicities were common in the late Triassic.text
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Cochrane, Justin Michael. "Diagenetic carbonates and biogeochemical cycling of organic matter in selected Archean-Paleoproterozoic sedimentary successions of the Kaapvaal Craton, South Africa." Thesis, 2010. http://hdl.handle.net/10210/3288.
Full textAbstract:
M.Sc.The Kaapvaal craton is one of few regions on earth with an almost continuous record of wellpreserved supracrustal rocks ranging in age from ~3.5 Ga to the late Paleoproterozoic at ~1.75 Ga. In this study diagenetic carbonates from the Paleoarchean Buck Reef Chert and Joe’s Luck Formation of the Swaziland Supergroup, the Mesoarchean Thalu and Promise Formations of the Mozaan/Witwatersrand Supergroups and the Paleoproterozoic Timeball Hill and Silverton Formations of the Transvaal Supergroup were sampled and analyzed. The aim of the study was to determine possible variations in the composition of the carbonates through time and their significance especially with regards to microbial activity in diagenetic systems in early Earth history. Results indicate similar petrographic observations and geochemical signatures in diagenetic carbonates of iron formations in the Buck Reef Chert, Joe’s Luck and Griquatown Iron Formation. The carbonates all tend to be siderites with iron derived from hydrothermal input and all are depleted in 13C relative to Peedee Belemnite standard. It suggested that siderite formed as a result of microbial respiration. Microbes degrade organic matter and reduce iron in this process. This resulted in the depletion in 13C and in the precipitation of siderite. However in order for iron reduction to have occurred the reduced iron first had to be oxidized. This most probably occurred through iron oxidizing chemolithoautotrophs under microaerophilic conditions. Diagenetic carbonate concretions of the Thalu and Promise Formations are manganiferous and are highly depleted in 13C relative to PDB. There is also strong evidence for hydrothermal input of manganese and iron into the system because of positive europium anomalies. The carbonates from both of the formations strongly suggest the presence of some free oxygen. The reasoning behind this conclusion is as follows: The depletion of 13C in the carbonates points to microbial decomposition of organic matter and manganese respiration (the decomposition of organic matter by microbial MnO2 reduction) is shown to be the most reasonable process that led to the formation of the carbonate concretions. The implication is that MnO2 must first have been precipitated and that can only be achieved in the presence of free oxygen with the oxidation reaction often catalyzed by manganese oxidizing chemolithoautotrophs. The carbonates of the Timeball Hill and Silverton Formationsare calcites ad contain little no iron. There is also little or no evidence for hydrothermal input and the basin appears to be a clastic dominated. It is generally accepted that a major rise in oxygen in the oceans and the atmosphere occurred at about 2.32 Ga. This rise in oxygen levels is reflected in the diagenetic calcite concretions of the Silverton Formation. Both iron and manganese reduction where not very effective because of the depletion in the basin water of these two elements, organic carbon taken up in the calcite concretions, indicated by negative δ13CPDB carbonate values, was most probably derived from aerobic and/or nitrate respiration. The most important conclusion from this study is that sufficient free oxygen and hence oxygenic photosynthesis were present to oxidize both Fe and Mn at least as far back as the Paleo-Mesoarchean.
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Apak, Sukru N. "Structural development and control on stratigraphy and sedimentation in the Cooper Basin, northeastern South Australia and southwestern Queensland / by Sukru N. Apak." 1994. http://hdl.handle.net/2440/21506.
Full textAbstract:
Bibliography: leaves 94-105.xvi, 105, [91] leaves : ill. (some col), maps (some col.) ; 30 cm. 50 maps in box; 35 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 1995?
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Osburn, Keith Craig. "The nature and origin of the polymetallic Salt River massive sulfide deposit, Northern Cape Province, South Africa." Thesis, 2012. http://hdl.handle.net/10210/5022.
Full textAbstract:
M.Sc.The Salt River deposit is a poly-metallic base metal deposit with a Zn-Cu-Pb metal content that occurs southwest of the town of Kakamas within the Northern Cape Province, South Africa. The Salt River deposit occurs within the Geelvloer Formation of the Bushmanland Subprovince of the Proterozoic Namaqua Metamorphic Province (NMP). This study constitutes the first detailed study of the host rock succession to the Salt River deposit, by investigating the lithostratigraphy, petrography geochemistry and geochronology. During the course of the study, various styles of wall-rock alteration were identified and investigated to determine their effect on the host rock succession. A further aim of this study was to classify the Salt River deposit and compare it to neighboring deposits occurring in the NMP. Geochronological studies were undertaken to define the age of mineralization. Detailed logging of exploration diamond drill core combined with petrographic investigation was used to define thirteen distinct lithotypes. The stratigraphy is dominated by felsic grey gneisses and mafic amphibolites, minor calc-silicate rocks, granitic augen gneisses, pegmatites and two lithologies that represent the metamorphosed equivalents of hydrothermally-altered host rock. Lithostratigraphic investigations yielded a rather uniform succession containing four distinct marker beds defined by their common occurrence and ease of correlation across various boreholes.
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Coleman, Janet Marie Combes 1952. "Depositional systems and tectonic/eustatic history of the Oligocene Vicksburg episode of the northern Gulf Coast." 1990. http://hdl.handle.net/2152/20695.
Full textAbstract:
Regional depositional systems analyses combining surface and subsurface geological and geophysical data provide the framework for a sequence stratigraphic study of the Lower Oligocene Vicksburg Formation of the Gulf Coastal Plain. The results describe the eustatic history of the Vicksburg stratigraphic unit. The two primary Texas depocenters, the Houston embayment and the Rio Grande embayment, were separated by a deep-rooted structural nose: the San Marcos arch. A barrier / strandplain intervened between the Louisiana deltaic depocenter and the Houston embayment. Within the embayments, deltaic complexes merged along strike with barrier / strandplains. Contemporaneous growth faulting controlled deltaic depositional patterns in the Rio Grande embayment and, to a lesser degree, in the Houston embayment. Smaller wave-dominated delta complexes interspersed with barrier / strandplains extended across the San Marcos arch. Updip of the paralic depocenters, fluvial systems traversed coastal plain units. Seaward of the paralic systems, sand and mud deposits prograded across and built up over the relict Jackson shelf and shelf margin. The contact between the Vicksburg Formation and the underlying Jackson Group marks the position of the Eocene - Oligocene boundary within the Gulf Coastal Plain section. On regional dip-oriented well-log cross sections there is a distinct, abrupt, seaward shift in the paralic facies at the Jackson - Vicksburg boundary; this contact corresponds to an Exxon-model Type 1 unconformity. The unconformity is related to the development of an Antarctic ice sheet in the earliest Oligocene. During middle Vicksburg time, a minor transgression (genetic stratigraphic sequence boundary) flooded the coastal plain. Overlying the progradational Vicksburg Formation, the lower Frio Formation accumulated in an aggradational mode; this switch of depositional modes corresponds to an Exxon-model Type 2 sequence boundary. Construction of genetic stratigraphic sequence diagrams and comparison to Exxon's coastal onlap curves across different areas of the Oligocene coast show that the effects of local depocenters (sediment influx) may mask eustatic effects. Only truly regional events, such as the middle Vicksburg transgression and the basal Vicksburg seaward shift in coastal position, correlate across the coastal plain and may result from a eustatic change.text
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Witebsky, Susan. "Paleontology and sedimentology of the Haymond boulder beds (Martin Ranch), Marathon Basin, Trans-Pecos Texas." 1987. http://hdl.handle.net/2152/11931.
Full textAbstract:
A boulder bed unit in the upper Haymond Formation (Pennsylvanian), generally believed to be olistostromes, is exposed in the eastern Marathon Basin, west Texas. Two localities of this unit (Housetop Mountain and Clark Butte) contain clasts derived from several formations found within the basin, as well as exotic Devonian metamorphic and volcanic rocks. This report describes a third previously unstudied site (Martin Ranch locality) that contains clasts of exotic Middle Cambrian shelf limestones. These limestones provide a key to the Early Paleozoic history of the Marathon region. The boulder beds lie in the upper part of the Haymond Formation. At the Martin Ranch locality they form a zone that is traceable for 6.6 km along strike and is up to 230 m thick. These boulder beds contain interbedded units of massive, unstratified, pebble- to boulder-bearing mudstone, thickly bedded, massive sandstone, lenses of pebbly sandstone, and deformed flysch beds. About 80 percent of the clasts found in the boulder beds at Martin Ranch are chert derived from several basin formations. Unique displaced slabs of bedded chert pebble conglomerate comprise about 10 percent of the clasts. Theses conglomerates were probably derived from upper fan-channel deposits within the lower Haymond Formation. Pennsylvanian limestone clasts redeposited from the basin facies of the Dimple Formation and clasts of exotic, late Middle Cambrian limestones each comprise about 5 percent of the clasts. These Cambrian limestones, older than any formation in the Marathon Basin, contain a fauna characteristic of the seaward edge of the cratonic carbonate shelf. The presence of the Cambrian clasts constrains the location of the North American shelf edge during the Cambrian, placing it at least 120 km southeast of the present day Marathon Basin. Both the Martin Ranch and Housetop Mountain boulder beds are composed mainly of clast-bearing, matrix-supported mudstone which have pebbly sandstone, massive sandstone, and flysch beds interstratified with the mudstone and represent periodic deposition of debris flows, slumps, slides, and turbidites interspersed with normal basin deposition of flysch facies rocks. However, different clast types are found at the two localities. The Martin Ranch locality has clasts of Cambrian limestone and chert pebble conglomerate, the latter up to 90 m in length, that are absent at the other localities. Exotic Pennsylvanian limestone clasts and exotic Devonian metamorphic and volcanic rocks, common at Housetop Mountain, are rare or missing at Martin Ranch. The Clark Butte locality is unique because it lacks the mudstone which dominates the other two localities. Instead, the matrix is composed of a pebbly sandstone and conglomerate associated with thick sandstone beds. The boulder beds at this locality may represent upper fan channels and channel-lag deposits. The turbidites and olistostromes resulted from recycling of the southern edge of the tectonic basin as the advancing Ouachita thrusts uplifted the pre Haymond strata. Most of the clasts were from older basin formations exposed by these faults; however one of these thrusts also uplifted slivers of exotic Middle Cambrian limestone. Earthquakes probably triggered slumps and rock falls off the fault scarps. As the boulders travelled downslope plowing through the slope sediments, they accumulated more material. This combination of slide debris and slope mud turned the slumps and slides into debris flows. Between episodes of debris flows and turbidity currents, normal basin deposition of thinly bedded turbiditic sandstone and pelagic shale occurred.text